Parting tool for ML7

[GrottoParticipant @grotto]

I've got a Myford ML7 with QC tool post.

I've tried a few (inexpensive) parting tools, and one medium priced (replaceable carbide insert), but am stil not getting good cuts in anything over 15mm in mild steel. I think everything else is OK, and it's just the tool that is causing the issue.

Can anyone recommend a decent holder/blade?

Although my tool holders take 12mm tools, I can't get them low enough to be at centre height (had to mill a couple of mm of my indexable tool).

[GrottoParticipant @grotto]

[GrottoParticipant @grotto]

Found an old thread on here which had a load of good info.

Kit-Q-Cut seemed to be rated highly, another (less expensive) option is the Glanz from RDG.

Anyone know if the Kit-Q much better?.

I'll check of I can get replacement tips here in NZ.

[HopperParticipant @hopper]

Make life easy for yourself and set up a rear toolpost for parting.

[GrottoParticipant @grotto]

thanksThe old thread I read talked about rear toolpost for parting, but a few people reckoned if you had a decent parting tool you didn't need to go down that road.

I've never used a rear toolpost and don't know anything about them, other Han you use them for parting.

Are they used for anything else?

Are they a hassle to set up (do you leave them on, or have to remove them when not in use)?

If I'm going down that road, what's a good model to get?

[john carruthersParticipant @johncarruthers46255]

On my sc3 I use the usual front tool post but run the lathe in reverse for parting, with the tool upside down. I used 1" stainless the other day parting an eccentric so a bit of an interrupted cut to start with. Just a hss 8mm square tool ground down to 3/32, no 'top' rake, cuts most things sweetly.

[LambtonParticipant @lambton]

On my sc3 I use the usual front tool post but run the lathe in reverse for parting, with the tool upside down. I used 1" stainless the other day parting an eccentric so a bit of an interrupted cut to start with. Just a hss 8mm square tool ground down to 3/32, no 'top' rake, cuts most things sweetly.

This is an absolute no no with any Myford lathe as the chuck will unscrew!

[john carruthersParticipant @johncarruthers46255]

How quaint

[egaParticipant @ega]

Grotto:

"Kit-Q-Cut seemed to be rated highly, another (less expensive) option is the Glanz from RDG"

I have experience of both these and am confident that the Sandvik tool is significantly better.

To get the most out of a rear toolpost you do need a long topslide.

[mechman48Participant @mechman48]

I have a WM 250V-F & for the small amount of parting off I've done have used a small front mounted set up; I have made a rear mounted tool post made from 'Hemingway' kit for some large dia. steel test pieces, thick clamping washers, & that too works fine, there are some pics in my album 'rear tool post' if you want to peruse.

George.

[egaParticipant @ega]

mechman48:

Am I right that the last photo in your album shows the Kit-Q-Cut? This tool is certainly capable of working very well indeed although I have some reservations about the way that Greenwood Tools have adapted the Sandvik blade so that it is held by screws in shear rather than the normal clamp. I would accept that if a serious digin occurs and "something has to give" then it might be best for the screws to let go rather than, say, wreck the cross slide as happened to the late Martin Cleeve.

[VicParticipant @vic]

I bought one of these a little while back and it works great.

**LINK**

[GrottoParticipant @grotto]

Thanks for the advice.

I don't have a long top slide, just the standard one. Would this mean I would have to remove the rear tool post when it's not in use?

I did think about the Hemmingway kit, but don't have a mill, and I'm not 100% confident I'd make a good job of it.

I'm tossing up if I should get the Kit-q-cut, or a rear toolpost with replaceable tips.

[Enough!Participant @enough]

Posted by Grotto on 21/11/2015 02:45:30:

thanksThe old thread I read talked about rear toolpost for parting, but a few people reckoned if you had a decent parting tool you didn't need to go down that road.

I find it's best to judge comments/opinions like this in the context of whether the person has actually tried the tool/method under discussion.

[T.BParticipant @t-b-2]

I would have to agree with Ega ,

I have both the Kit-Q-Cut and Glanze parting tools .The Glanze one is never used in preference over the other, although I think the inserts for the Kit-Q-Cut are very expensive in comparison , they do seem to last a long time.

[egaParticipant @ega]

Grotto:

"I don't have a long top slide, just the standard one. Would this mean I would have to remove the rear tool post when it's not in use?"

I think the answer to your question, as to so many others, is to be found in the GHT book (or the earlier work of Duplex). In short, the standard ML7 cross slide will certainly take a rear toolpost but there will obviously be less leeway around the work, toolpost and tailstock.

If you are unsure, why not locate someone near to you who has an RTP to demonstrate (I would be glad to do so but I am probably nowhere near you)

[IanTParticipant @iant]

For smaller work on my lathes, I generally just use various HSS parting tools held in the front tool post/block. I have a range of tool holders set-up for different sized blades and materials. Provided nothing is over-extended, this works fine. I do not generally use inserted tools (apart from roughing castings) preferring HSS for most of my work..

However, for larger diameter parts (you mentioned steel over 15mm diameter) I use a NCIH26-3 inset tool mounted in a rear tool post on my elderly S7. This will part 50mm mild steel with ease, although I will admit to holding my breath when doing so. The only problem I've had was when trying to part a piece that involved an interrupted cut – and the insert chipped. I used a smaller HSS parting blade to get past the 'corners' of the work – making several passes to widen the cut out to 3mm – and then successfully finished the cut with a new insert.

From memory, I purchased the rear tool holder for the blade from RDG but I can't find it on their site now. At the time it was quite a bit cheaper than the Q-Cut. Although I have the long table – I don't tend to leave the rear tool post mounted. I don't part very large work that often – so prefer it to be in it's box out the way. It takes just a few minutes to mount when needed, as there is no height adjustment required. I just pull the blade out sufficiently to part the work. My set-up is similar to that shown below.

Regards,

IanT

[David Clark 13Participant @davidclark13]

There was a rear parting off tool for the Myford ML7 Short cross slide in an early MEW. I expect you can find the plans in an online index. If you get totally stuck I can probably find plans for the one I designed and post them here.

[IanTParticipant @iant]

Had a look around for a similar tool-post to mine and eventually found this one at Chronos (so maybe mine wasn't from RDG?).

**LINK**

It looks to be pretty much the same design for the actual tool-post but the insert blade may be a different make – as long as it holds the inserts securely it probably doesn't matter too much..

I was thinking about this earlier and apart from the usual arguments about the benefits of using a rear tool post – these insets have a 'V' shaped nose (very much as GHT suggested) that probably does shape & curl the swarf quite efficiently. Anyway, it certainly works well and is very quick and easy to mount/dismount as required….

Regards,

IanT

[GrottoParticipant @grotto]

Thanks for all the helpful replies.

Based on the positive comments from users of the kit-q-cut I'm planning on ordering one of those.

I'll look at getting a rear tool post for parting larger diameter rods which I do occasionally.

As an aside, I tightened/adjusted the jib screws on my lathe yesterday, and it seems to be parting better with my current tool, so I reckon that was part of the problem.

[mechman48Participant @mechman48]

ega

… Am I right that the last photo in your album shows the Kit-Q-Cut?

I don't have one of these; the tool holder shown is of similar type as this … middle, top row…

**LINK**

used upside down in my rear tool post.

George.

[Rufus RoughcutParticipant @rufusroughcut]

Hi Grotto

JB Cutting tools do an indexable parting blade and holder to suit QCTP for front use, I've parted off 2"+ bars of Mild, Stainless, cast, alli and brass no probs with a bit of WD40 as a lube on my ML7, guess I'm just lucky, I have also found in the past that the thumb screw height adjustment part of the QCTP tool holders didn't allow for extreme lowering or extreme highering of the cut centre so I made new ones to accommodate and have even shaved 5mm off the corner of a spare ML10 top slide to get the holders low enough to centre them on my ML10.

I've found in my experience that firm continuous controlled infeed makes a better cooler cut rather than gradually sneaking the parting tool through, it's also worth noting that I have reground the carbide inserts and got a sharper cleaner cut from that of the un-ground new ones.

info which may be worthless to many but invaluable to a few should always be free, ignore it or try it enjoy

[RobboParticipant @robbo]

[Jon GibbsParticipant @jongibbs59756]

I bought a cheap chronos rear toolpost for parting on my ML7 as others have suggested. Although I have a short cross-slide it's the work of a moment to mount and demount it when it's needed when working larger stock.

This means parting is painless and trouble free.

I also modified the blade mount to take narrower blades which work even better IMHO – For more details see here…

**LINK**

I've never needed the larger blade since I made the mod but I still have it in case

HTH

Jon

[Howard LewisParticipant @howardlewis46836]

When I had a ML7, I made a Rear Toolpost. With the toolholder mounted inverted, it functioned very well.

The tool now lives in the shop made 4 way RTP (along with front and back chamfer tools) on my current lathe, and despite being deliberately ground at an angle, very rarely causes problems.

Also, a 2mm Garmin parting tool, from JB Cutting Tools, is used occasionally, in the front toolpost. This has a V groove form, and swarf does not jam up, and again, very rarely digs in. Being Carbide, the tips do not like interrupted cuts, and chip. Nevertheless; highly recommended.

Even if you have to remove it for most use, my advice is to buy/make a Rear Tool Post .

As already said, maintain a steady, slow infeed, to prevent the tool from rubbing.

Additionally, for large diameter ( 12mm +) bar, I nearly always rig a gravity drip feed of soluble or neat oil onto the blade.

Some of this may help.

Howard

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